Adequate blood pressure control: perception and reality.

Blood pressure should be controlled over 24 h to reduce or prevent cardiac hypertrophy and reduce the prevalence of sudden death, myocardial infarction and myocardial ischaemia at the time of the morning rise in blood pressure. Anti-hypertensive medication is usually given once-daily in the morning and the dose is titrated on the basis of post-dose (peak) blood pressure. This frequently leads to inadequate control prior to the next drug dose unless drugs with appropriate pharmacokinetics or pharmacodynamics are used. ACE inhibitors exhibit an E(max) plasma concentration: blood pressure response relationship, and thus short-acting ACE inhibitors can exert an effect over 24 h if titrated based on pre-dose (trough) blood pressure. However, when titrated in clinical practice on post-dose (peak) blood pressure response, doses are used that are inadequate to control blood pressure for 24 h. ACE inhibitors with appropriate pharmacokinetics such as perindopril can control blood pressure when titrated at peak provided a dose is used (4 or 8 mg) that is known to have a T:P close to 1.0. Shorter-acting ACE inhibitors frequently give inadequate control when titrated at peak. An understanding of the pharmacokinetics and pharmacodynamics of a drug, coupled with knowledge of the time the drug was taken, together with the time of blood pressure measurements, enables control to be achieved with once-daily therapy even if the drug is titrated at peak response.